Si sviluppa, per le funzioni (non necessariamente analitiche) di una
variabile complessa, un analogo del classico Calcolo differenziale
e integrale, basato su un'estensione delle nozioni di derivata e integrale
complessi (derivata media, integrale medio). An analogous of the elementary Calcolous of a real variable is outlined
for functions (non analyric, possibly) of a complex variable. The
start-point is a generalized definition of the complex derivate (mean
derivative), that for $C^{1}$functions coincides with the formal
operator $\delta/\delta^{z},$and an analogous extension of the complex
integral (mean definite integral). The principal results of the real
Calculus remain valid in $C$. For analytic functions, in particular,
one obtains new proofs of some classical theorems (GOURSAT, MORERA).
